A firefight is reported to have erupted in Syria's capital, Damascus, between the rebel Free Syria Army and the forces of President Bashar al-Assad.
Witnesses say the sound of machine-guns and rocket-propelled grenades were heard from the district of al-Mezze.
The neighbourhood, in the centre of Damascus, is home to several security facilities and is one of the most heavily guarded parts of the capital.
A car bomb exploded in the northern Syrian city of Aleppo yesterday, killing at least two people and injuring 30 others.
A day earlier, at least 27 people were reported to have been killed and 97 wounded in two explosions in the capital.
State TV described the blasts as terrorist attacks.
However, activists have accused the authorities of staging incidents to discredit opposition groups.